No load voltage at power outlet fuse, yet power outlet is working. ?

Just not sure how to proceed. Gota take care of it because I'm sure that current is going somewhere. I believe the alt fuse is in charge of the power outlet. Does this mean it takes over if there's something wrong?

 

Are you saying the Power Outlet fuse has no power, but the outlets are working?

As for the alt fuse, it doesn’t “take over”.
Once a fuse blows, no electricity flows through it.
If for some reason you have a “bad” fuse that doesn’t blow, then the alt fuse would blow. (Maybe)
But your going to have lots of smoke and smell before that happens. As the outlet wires aren’t going to handle 120A of draw. They are going melt.

 

At the fuse plug, fuse removed, key at acc or on, there is no voltage on the load side. Only the ground side. I also plugged in a phone charger just in case it needed something to activate it....

 

Which power outlet are you checking? Mine has 3, and one of them is wired separately from the others.

 

According to the diagram you provided. The power from the alt goes through a 15 amp power outlet fuse (light blue trace). This provides power to the outlet (p13, p14). The “green” trace activates the relay, it closes the switch which powers the (blue trace), power outlet.

If the alt fuse is out there should be no power to the outlet (p13, p14). If there is I would be suspicious of the relay and/or how the relay is wired in the circuit.

 

If the alt fuse is out. The whole truck won’t run.

There isn’t a ground side of a fuse.
With the fuse removed. You will see voltage to one side. And nothing on the other.

 

You mean the 15amp power fuse socket ?

There is no ground side ! You never have a ground in a simple DC circuit till the current has passed through the load . The load being a relay coil or anything that uses current.

My head hurts !

 

Ok. So let’s try it this way.
There is a diagram in the FSM that shows what I thought was the ground path of the fuses & relays in the engine junction box.

I’ll post a pic because I’m really curious what the point of it is.

Anyway, If I put one probe to ground & the other to each of the outer fuse connections (the points they show in this diagram), I get battery voltage. If I do the same down the inner fuse terms, with the exception of “dome”, which has a drop of 1.42 volts, I get 0. (The drop seems to vary though.)

Then if I put the probe to battery pos & check the inner terms of the fuse connectors, I get voltage, with the exception of power outlet.

This is all key off.

Then with key at start & acc

Same thing as above with some variance in voltage at inner terms.
Still 0 at power outlet.
Relay gets warm if that makes any dif.

& maybe I have my wording all wrong. Maybe that isn’t ground. Maybe none of this means anything….

 

Apologies. This is one I did not remove. This is all with the lower amp fuses removed.

 

I have two & they are spliced at the kick panel.

 

What problem are you trying to solve? Do you have a parasitic drain killing the battery overnight or something?

 

I'll betcha mine hurts more....

 

No. It is not a ground issue. There is some phantom .82v drop I am trying to find. As I put it, flailing around. It ends up being a total drop of 1.17 volts (pos) at startup. I originally thought it was at the load side of the EFI relay, however in removing the EFI fuse, it's no longer present there. I read if you remove loads & move closer to the battery whilst checking voltage, you may find the culprit.

I have a high idle & my CEL light does not come on at startup.

 

This is normal. The only reason the relay is there is to break the circuit. If the relay wasn’t there, and you left something in the power out, it could drain the battery.

You will never see power or ground to the inner terminals unless something is in the the outlet itself, in the truck. And I don’t recommend putting something in the outlet to test the fuse terminal. You could potentially draw too much current through your meter and blow the internal fuse. Or worse, fry the meter.

 

Define high idle??

A high idle to me would mean 2000 rpm plus I would need to look I really don`t pay attention my cold start idle is around 1500 rpm.

Your CEL does not light with the ignition switch in the run position ? It does light when a code is tripped or not?

****Are you maybe confusing Volts with Amps ??*****



Are you using a Calibrated Certified Meter ?? Like I needed to certify welding machine output .

Between meter error and old age of the vehicle a meter reading showing a voltage drop is quite possible.

In theory the system voltage should be the same any place on the vehicle with constant power .

line loss and other factors will cause minor differences .

in DC circuits long ago I was always taught to use the negative side of the power source ( battery) as my ground. I have quite a selection of test leads.

What problem is this minor voltage loss causing ??

What you describe is trouble shooting for current draw .

a unknown current draw that completely drains the battery in a few hours.

I know My head hurts when the pain from everything else is no longer noticed.

I really wish I was closer to help in person.

 

Mine is around 1100. I had gotten it down to around 900, however I just put in a new a/t vss & gear in the tc vss & now it’s at 1100. Go figure….
Anyway, my understanding is the ideal idle is 650-750. I’d be good with 800. Be nice if it wouldn’t shudder when I’m turning it off, as though it’s got extra fuel it’s thinkin it needs to be using. There is always 3.6 for the ltft reading when I start it. Just something I noticed. Significant or not, I don’t know.

The cel does not come on when key is in the start position. & I am getting no voltage at the ECU for it, so my guess is it will not trip.

My speedometer was out of specs, hence the vss stuff because that’s one of the places the FSM directs you when this, as well as the “missing” light occurs.

I did a voltage drop test battery pos to pos control side of the EFI relay & got 1.17.

As far as amps, I’m not messing with them unless I was walked through it or unless checking for a parasitic drain.

I don’t know if the meter is certified. It’s a decent one. Amprobe-

So I was under the impression that if the problem was ignition or key on dependent, then it wouldn’t necessarily result in a parasitic drain.

& per usual, conflicting info as to what constitutes a minor draw. I thought 1.17 was not so minor.

 

**** Your seeing a voltage drop not a draw there is a difference**A draw would be measured in Amps!!!

You have no friends local that can help ? Troubling shooting electrical issues is best done in person .

When you post numbers please include what they are. RPM or VDC etc.

Maybe find a book on simple DC circuits to understand the basic concepts and terms which for DC circuits are all the same. I am old fashioned I would rather read then watch.

 

Yes. That’s what I put, voltage drop. 1.17v drop.

 

Ok. Then here are the readings I get with truck off. Hasn’t been started this morning. Nothing in the outlets. Radio of including illumination.

Dome - starts at 9v inner post to pos battery term 3.6v inner post to neg term. Then an exchange occurs. Pos increases, neg decreases until it gets to 11v pos & 1.6v neg.

EFI - 12.07v inner term to pos battery term with or without relay in

Alt-s - 12.45 inner term to pos battery term.